werkdock/internal/build/dockerfile_test.go

package build

import (
	"reflect"
	"strings"
	"testing"
)

func TestParseReadsTheStageOneInstructions(t *testing.T) {
	tests := []struct {
		name string
		in   string
		want []Instruction
	}{
		{
			"comments and blank lines are dropped",
			"# a build environment\n\nFROM debian:trixie\n\n# install\nRUN apt-get update\n",
			[]Instruction{
				{Keyword: "FROM", Args: "debian:trixie", Line: 3},
				{Keyword: "RUN", Args: "apt-get update", Line: 6},
			},
		},
		{
			"a line continuation joins into one instruction",
			"FROM debian:trixie\nRUN apt-get update \\\n && apt-get install -y jq \\\n && rm -rf /var/lib/apt/lists/*\n",
			[]Instruction{
				{Keyword: "FROM", Args: "debian:trixie", Line: 1},
				{Keyword: "RUN", Args: "apt-get update && apt-get install -y jq && rm -rf /var/lib/apt/lists/*", Line: 2},
			},
		},
		{
			"a comment inside a continuation is dropped, as in docker",
			"FROM base\nRUN one \\\n# explaining the second half\n && two\n",
			[]Instruction{
				{Keyword: "FROM", Args: "base", Line: 1},
				{Keyword: "RUN", Args: "one && two", Line: 2},
			},
		},
		{
			"keywords are case-insensitive and normalized",
			"from base\nrun true\ncmd [\"/bin/sh\"]\n",
			[]Instruction{
				{Keyword: "FROM", Args: "base", Line: 1},
				{Keyword: "RUN", Args: "true", Line: 2},
				{Keyword: "CMD", Args: `["/bin/sh"]`, Line: 3},
			},
		},
		{
			"the metadata instructions pass through verbatim",
			"FROM base\nENV JAVA_HOME=/opt/java\nWORKDIR /work\nLABEL org.opencontainers.image.title=\"build\"\nENTRYPOINT [\"/entry\"]\nCMD [\"-v\"]\nVOLUME /data\nUSER 1000\n",
			[]Instruction{
				{Keyword: "FROM", Args: "base", Line: 1},
				{Keyword: "ENV", Args: "JAVA_HOME=/opt/java", Line: 2},
				{Keyword: "WORKDIR", Args: "/work", Line: 3},
				{Keyword: "LABEL", Args: `org.opencontainers.image.title="build"`, Line: 4},
				{Keyword: "ENTRYPOINT", Args: `["/entry"]`, Line: 5},
				{Keyword: "CMD", Args: `["-v"]`, Line: 6},
				{Keyword: "VOLUME", Args: "/data", Line: 7},
				{Keyword: "USER", Args: "1000", Line: 8},
			},
		},
		{
			"trailing whitespace and a final line without a newline",
			"FROM base   \nCOPY app /srv/app",
			[]Instruction{
				{Keyword: "FROM", Args: "base", Line: 1},
				{Keyword: "COPY", Args: "app /srv/app", Line: 2},
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := Parse(strings.NewReader(tt.in))
			if err != nil {
				t.Fatal(err)
			}
			if !reflect.DeepEqual(got, tt.want) {
				t.Errorf("instructions:\n got %+v\nwant %+v", got, tt.want)
			}
		})
	}
}

func TestParseRefusesWithTheReason(t *testing.T) {
	tests := []struct {
		name    string
		in      string
		wantErr string
	}{
		{"no FROM first", "RUN true\n", "begins with FROM"},
		{"empty file", "# nothing but a comment\n", "holds no instruction"},
		{"unknown instruction", "FROM base\nFRobNICATE x\n", "unknown instruction FROBNICATE"},
		{"EXPOSE", "FROM base\nEXPOSE 8080\n", "shares the host's network"},
		{"HEALTHCHECK", "FROM base\nHEALTHCHECK CMD curl -f http://localhost/\n", "no daemon to poll"},
		{"STOPSIGNAL", "FROM base\nSTOPSIGNAL SIGQUIT\n", "stop sends SIGTERM"},
		{"ONBUILD", "FROM base\nONBUILD RUN true\n", "ONBUILD trigger"},
		{"MAINTAINER", "FROM base\nMAINTAINER me\n", "deprecated by docker itself"},
		{"ARG is a later stage", "FROM base\nARG VERSION=1\n", "stage 2 of RFC 0006"},
		{"SHELL is a later stage", "FROM base\nSHELL [\"/bin/bash\", \"-c\"]\n", "stage 2 of RFC 0006"},
		{"ADD is a later stage", "FROM base\nADD app.tar /srv\n", "stage 2 of RFC 0006"},
		{"an instruction without an argument", "FROM base\nRUN\n", "RUN needs an argument"},
		{"the refusal names the line", "FROM base\nRUN true\nEXPOSE 80\n", "line 3"},
		{"RUN --mount", "FROM base\nRUN --mount=type=cache,target=/var/cache/apt apt-get update\n", "RUN --mount is not supported: a RUN step cannot mount"},
		{"RUN --network", "FROM base\nRUN --network=none true\n", "RUN --network is not supported"},
		{"RUN --security", "FROM base\nRUN --security=insecure true\n", "RUN --security is not supported"},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			_, err := Parse(strings.NewReader(tt.in))
			if err == nil || !strings.Contains(err.Error(), tt.wantErr) {
				t.Errorf("got error %v, want it to contain %q", err, tt.wantErr)
			}
		})
	}
}

func TestChangesTreeSeparatesStepsFromMetadata(t *testing.T) {
	for _, keyword := range []string{"FROM", "RUN", "COPY"} {
		if !(Instruction{Keyword: keyword}).changesTree() {
			t.Errorf("%s changes the work tree", keyword)
		}
	}
	for _, keyword := range []string{"ENTRYPOINT", "CMD", "ENV", "WORKDIR", "USER", "VOLUME", "LABEL"} {
		if (Instruction{Keyword: keyword}).changesTree() {
			t.Errorf("%s is metadata, not a tree change", keyword)
		}
	}
}